It is well known in the pharmaceutical art that tablets may be formed with a groove or score marking to facilitate breakage of the tablet into sub-dosage units. Typically, these tablets are configurated circularly with a transverse score marking disposed along the top surface of the tablet such that the tablet may be severed into half-sections. One example of such a tablet is that disclosed by Geller, in U.S. Pat. No. 3,883,647. Another example of a tablet having surface score lines and a circular configuration except severable into quarter-sections is the maltese-cross scored tablet disclosed by Langauer in U.S. Pat. No. 3,723,614.
Because of the inherent difficulties of breaking a grooved tablet into accurate predetermined parts, a variety of diverse attempts have been made in the prior art seeking tablet structures which are readily fractured into sub-dosage units by application of moderate manual pressure. One example of such an attempt is that disclosed by Kraus et al, in U.S. Pat. No. 3,336,200, where two half sections having a highly tapered top surface which join at a score line positioned along the tablet's diameter. These diverse attempts to improve the convenience and accuracy of breaking a grooved tablet into predetermined parts have achieved limited success as best.
Inherently, the problem of breaking a grooved circular tablet resides in the hardness factor which results from tablet forming presses coupled with the small size configuration which does not allow for either ease of handling or breaking. A typical attempt to sever such circular tablet is by means of a sharp knife or related instrument which results more often than not, in fracture of the tablet into undesired miniature pieces. In cases where the severing into two pieces is successful, the pressure which is required along the score marking frequently propels both sections from the initial location unless extreme care is used to contain the two pieces during the breaking operation.
In order to overcome the problem of breaking circular tablets because of the hardness factor and small size, prior art attempts have also been made to configurate oblong tablets having score lines disposed transversely along the top surface. One example of such a tablet is that disclosed by Zellers in U.S. Pat. No. 2,052,376. These oblong tablet configurations have also realized limited success in providing a solution to a readily, accurately severable unitary dosage tablet into sub-dosage units. Also, although tablets such as those disclosed by Zellers are oblong in appearance, the transverse cross-sectional configuration thereof is typically cylindrical. This configuration invites disadvantages associated with inclusion of sufficient amounts of active ingredients in a configuration which may be readily consumed without suffering patient discomfort.
One of the well recognized advantages of having a readily dividable tablet is that it permits the administration of a plurality of sub-dosage units thereby avoiding costs for specially preparing an individual tablet for each dosage unit. Also, active ingredients are rendered more highly stable in larger dosage units and correspondingly the useful self-life for larger dosage units is extended significantly beyond that for the smaller individual dosage units.
It has now been found that by practice of the present invention, unitary dosage tablets may be prepared having specially disposed score markings which permit breakage of the unitary dosage tablet into at least either bisectional or trisectional equivalent sub-dosage units in a convenient accurate manner. Thus, a number of the disadvantages inherent in prior art attempts to provide a solution to tablet breakage into accurate sub-dosage units which may be conveniently consumed by a patient have now been overcome by practice of the present invention.